Sheet Forming Research Articles

Mechanical upcycling of single-use face mask waste into high-performance composites: An ecofriendly approach with cost-benefit analysis

The COVID-19 pandemic created an unprecedented demand for PPE, with single-use face masks emerging as a critical tool in containing virus transmission. However, the extensive use and improper disposal of these single-use face masks, predominantly composed of non-biodegradable plastics, has exacerbated environmental challenges. This research presents an innovative method for mechanically upcycling PPEs used in medical sectors i.e. single use face masks. The study investigates a facile approach for reclamation of infection-free and pure polypropylene (PP) plastic from discarded single use face masks (W-PP) and blends it with various vegetable oil percentages (5, 10 and 20 %), resulting in a versatile material suitable for various applications. Melt flow index, rheological behaviour, DSC and FTIR were employed to investigate the effect of vegetable oil/radical initiator through chemical grafting on W-PP properties. The results demonstrate significant enhancements in the tensile strength and modulus of W-PP when blended with vegetable oil and a radical initiator. There was a marked increase in tensile strength (33 %) and strain (55 %) compared to untreated W-PP, rendering W-PP both robust and flexible. Furthermore, we employed this upcycled W-PP in the fabrication of glass fibre-reinforced composites, resulting in notable enhancements in both tensile strength and impact resistance. The upcycled W-PP demonstrates excellent potential for various applications, such as sheet forming and 3D printing, where the non-brittleness of plastics plays a pivotal role in manufacturing high-quality products. The cost-benefit analysis of this approach underscores the potential of upcycling PPE waste as a sustainable solution to mitigate plastic pollution and conserve valuable resources. The applications of this upcycled material span a wide range of industries, including automotive composites, packaging, and 3D printing.

SnO-SnO<sub>2</sub> Nanocomposites Based pn Diode: <i>In Situ</i> Synthesis, Characterization and Fabrication of Device for pn Diode Applicability

We report on an approach for the in-situ synthesis (chemical method based) of SnO-SnO2 nanocomposites followed by characterisation (including morphological, chemical, structural and optical) and investigation of the electrical properties of the nanocomposites with reference to the as-synthesized SnO2 nanoparticles. Compared to spherical SnO2 particles, the SnO phase is found existing in the form of sheet like morphology. It has been found that through controlling of the Sn:OH precursor ratio is effective for the achievement of SnO phase. Compared to the pristine SnO2 nanoparticles, the current-voltage (I-V) characteristics of the nanocomposites show the p-n junction characteristics. The observation of rectification ratio 2.05 indicates the excellent rectifying property of the nanocomposites due to the presence of p-type SnO phase. Further, exploration of the I-V characteristics has revealed the dominance of space-charge limited current transport mechanism for the nanocomposites sample. The lattice defects are discovered to be the cause of the transport mechanism in the nanocomposites sample.

Improvement of the Dimensional Accuracy of a Ti-6Al-4V Ripple Disc During Electric Hot Incremental Sheet Forming

The edge warpage of a Ti-6Al-4V ripple disc is a major forming defect during electric hot incremental forming, which can lead to a significant dimensional error. In this paper, a novel manufacturing method, namely the combination of electric hot incremental forming and electrically assisted sizing, has been proposed to improve the forming defect. The effect of process parameters on forming fracture was analysed in detail, and then an optimal combination of process parameters was obtained to ensure the successful forming of a Ti-6Al-4V ripple disc. On this basis, a sizing device and a sizing current were separately designed and analysed to eliminate the warpage defect of Ti-6Al-4V ripple discs. According to the experimental result, Ti-6Al-4V ripple discs can be satisfactorily fabricated through the method proposed.

Development of History Problems Based on Higher Order Thinking Skills (HOTS) Using Anderson Krathwohl Taxonomy

This study aims to 1) analyze the condition of the historical electronic module currently used at SMA Banda Aceh, especially in class XII Indonesian history subjects, 2) describe the development of the historical electronic module that was developed, and 3) describe the feasibility level of the electronic module that has been developed. This research is a type of R D research by adopting the development model of Borg and Gall. To produce this historical electronic module, researchers adopted two stages of development, namely the preliminary research stage and the development research stage. In the preliminary research stage, the researcher conducted a library study and observation. In the development research stage, the researchers carried out module designs, validated with experts and educators, revised, and conducted initial trials on six class XII students at SMA Banda Aceh. The research process was carried out using research instruments in the form of validation sheets and questionnaires. The results showed that 1) the historical electronic module used at SMA Banda Aceh in class XII is a module from the Kemendikbud, 2) the process of developing this module was carried out using Heyzine media in accordance with the advice of experts and educators, the initial trial process was carried out on six students with the final results of PBL-based historical electronic modules for class XII students at SMA Banda Aceh are very suitable for use, with a score of 98% from module experts, 88% from material experts, 86% from educators, and 90% from students.

Technical Guidance for Student Creativity and Achievement Program

The purpose of the student creativity program in general is to prepare future-oriented student resources and forged with higher education transformation so that they become superior, competitive, adaptive, flexible, productive, competitive graduates with Pancasila character, and guide students to become individuals who know and obey the rules, creative and innovative, as well as objective and cooperative in building intellectual diversity. While the objectives of the Student Achievement Program are: 1) giving awards to students who have achieved high achievements; 2) motivating students to carry out curricular, co-curricular, and extra-curricular activities as a vehicle for synergizing student hard skills and soft skills; 3) encouraging universities to develop a campus life climate that can facilitate students to achieve proud achievements on an ongoing basis; 4) Student entrepreneurship; and 5) MBKM activities in higher education. The method of delivering the material in the zoom meeting and offline, accompanied directly by selected expert presenters who are able to provide motivation and strategies and often participate in the intended achievement event in the FKIP Hall, Classroom, and other rooms that are useful in implementing activities that are planned to be carried out continuously or sustainably between April and December 2023. The activities are in the form of continuous technical guidance periodically until students are proficient in uploading activity websites, making implementation proposals, and creating achievement and entrepreneurial ideas. The data collection technique is observation, interview, and documentation. With data collection tools in the form of observation sheets, interviews, and documentation sheets. The target audience is students and lecturers, especially the mathematics education study program at FKIP Tanjungpura University. With the results obtained are: 1) many students are ready to make a team of service implementers starting from the preparation of proposals to the hope that the product will be accepted by the ministry and other institutions that oversee it; 2) students play an active role in participating in competitions or student achievement activities and compete starting from the institutional, regional, national, and international levels. The product of the service activity is in the form of a Student Creativity Program (PKM) proposal and empirical evidence of students participating in outstanding student activities then articles made and then published in the National Journal of Community Service.

The Development of Assessment Instrument Based on Wordwall to Measure Process Science Skills for Environmental Pollution

This study aims to determine the validity, practicality, and effectiveness of an assessment instruments based on Wordwall in measuring students' science process skills of junior high school science learning in environmental pollution materials. This research is a type of development research (Research and Development) that refers to the procedure of the Borg and Gall development model which has stages including research and information collecting, planning, develop the preliminary form of the product, product design validation, main product revisions, main field testing, operational product revision, operational field testing, final product revision. The subject of the study was a grade VII student of SMPN 2 Ajung, Jember. This study used instruments in the form of validation sheets, practicality sheets, student questionnaire sheets, and science process skills tests. Data analysis techniques used in research consist of validity test analysis, practicality test analysis, and effectiveness test analysis. The results showed that out of 20 multiple-choice questions developed from aspects of material, construction, and language based on the assessment of 3 validators were declared very valid and worthy of use without revision. The twenty multiple-choice questions tested have valid question item validity. The assessment instrument has a reliability value of 0.612. The difficulty level analysis obtained 5 easy criteria questions, 14 medium criteria questions, and 1 difficult criteria question. The effectiveness of the assessment instrument obtained the average results of students' science process skills of 55%, including the sufficient category and student response questionnaires of 81%, so they were declared very good.

Correction to: A comprehensive review on heat-assisted incremental sheet forming

Correction to: A comprehensive review on heat-assisted incremental sheet forming

In Situ Cutting Methodology with 3D Measurement of Block Excesses in Shipbuilding

_ The ship construction process is characterized by a sequential workflow, with pivotal workstations‡ playing a crucial role. Initially, steel plates are introduced to these stations in sheet form, undergoing a transformation process that culminates in the creation of segments known as blocks. These blocks are individually constructed and subsequently assembled at the final workstation, denoted as the block joining station. Upon completing block fabrication, a deliberate tolerance allowance is retained on the plates to accommodate deformations induced by heat treatment during the transformation from plates to blocks. The alignment process involves aligning the reference points (master reference line) of the blocks on a common axis, facilitating the identification of excess material and deformations. This alignment process encompasses aligning the blocks with each other, employing either a three-dimensional measurement device or manual methods to obtain necessary measurements for determining excess material. In an effort to optimize time spent on block alignment and machine usage, a comprehensive methodology has been developed. This methodology involves determining excess material cuts on the blocks, performing virtual alignment operations using laser scanning techniques in a virtual environment, and conducting the cutting process on the slipway prior to placing the block excesses on it. Keywords block excesses; scanning techniques; three-dimensional scanning technology

TABOO IN BUGINESE LANGUAGE SPOKEN IN TANJUNG KARANG VILLAGE: A DESCRIPTIVE QUALITATIVE STUDY

In Bugis culture, taboo language reflects the culture of Bugis society. This is part of the culture of the Bugis people, and the next generation really needs to understand these words. This research aims to identify taboo words, identify their forms, and analyze their references. This research was designed in the form of descriptive-qualitative research. This research was conducted in Tanjung Karang Village, Sebatik District, Nunukan Regency, North Kalimantan Province. Primary data in this research was collected using in-depth interview techniques. The researcher acts as the main instrument which is equipped with other instruments in the form of interview sheets. The data obtained was analyzed according to the research objectives. Taboo words, their forms and references were analyzed using the theories of Frazer (1955) and Montagu (1973). The research results show that the 45 taboo words can be grouped based on the use of taboo words about harmony with God (5 taboo words), the use of taboo words about harmony with humans (35 taboo words), and the use of taboo words about harmony with the environment (5 taboo words). Related to taboo in the form of 22 taboo names and taboo words, and 23 in the section on swear words, and related taboo references (12 references). Based on the list of taboo words above, it can be concluded that the term or name of taboo is often found and used in the Bugis language in the village of Tanjung Karang, especially in prohibitions which are called taboo in the sense that taboo is a word that when spoken contains magic, and prohibition. or an insult that makes someone offended if it is said.

Implementation of the Inquiry-Oriented RADEC Learning Model

The experiment activities carried out are not complete experiment activities. One of the learning models that includes investigative activities is the RADEC learning model. This research aims to implement inquiry-oriented RADEC learning. The method used in this research mixes methods by design-embedded experimental design. The subjects in this study were 45 elementary school students in class V, one of the elementary schools in Bandung Regency. Data collection techniques were collected using test and non-test instruments in the form of observation sheets, test questions, and questionnaires. Each stage of the RADEC learning model was good, with some stages increasing at each meeting and some optimally implemented. In investigative activities, students still need guidance in designing and making investigative reports and are required more than once to develop their skills in compiling, carrying out, and reporting investigations. Besides that, RADEC learning can increase students' mastery of concepts and encourage student collaboration skills.

Current Trends in Metallic Materials for Body Panels and Structural Members Used in the Automotive Industry.

The development of lightweight and durable materials for car body panels and load-bearing elements in the automotive industry results from the constant desire to reduce fuel consumption without reducing vehicle performance. The investigations mainly concern the use of these alloys in the automotive industry, which is characterised by mass production series. Increasing the share of lightweight metals in the entire structure is part of the effort to reduce fuel consumption and carbon dioxide emissions into the atmosphere. Taking into account environmental sustainability aspects, metal sheets are easier to recycle than composite materials. At the same time, the last decade has seen an increase in work related to the plastic forming of sheets made of non-ferrous metal alloys. This article provides an up-to-date systematic overview of the basic applications of metallic materials in the automotive industry. The article focuses on the four largest groups of metallic materials: steels, aluminium alloys, titanium alloys, and magnesium alloys. The work draws attention to the limitations in the development of individual material groups and potential development trends of materials used for car body panels and other structural components.

Substance Pressure Material Module-el Discovery Learning to Improve the Critical Thinking Ability of Middle School Students

The low critical thinking ability of Indonesian students is known based on the acquisition of PISA and TIMMS assessments with positions in the lower middle rankings. The lack of teaching materials that facilitate the improvement of critical thinking skills is one of the contributing factors. The purpose of this research and development is to produce a substance stress module to improve the critical thinking skills of junior high school students using model discovery learning. The development model used is 4-D, with stages including define (definition), design (planning), develop (development), and disseminate (spread). Data collection was carried out through a literature review, validation assessment, and e-module practicality response questionnaires. Data collection was carried out through instruments in the form of validation assessment sheets by practitioners and student practicality response questionnaire sheets. Practitioners assess the validity of teaching materials, while their practicality is assessed by students. The results of the material validation were 89.2% (very valid), the media validation was 90% (very valid), the student practicality questionnaire was 76.2% (practical), and the N-gain score was 0.46. These results indicate that the science modules developed are valid and practical for use in science learning

Perbedaan Kemampuan Penalaran Matematis Siswa Menggunakan Model Pembelajaran Discovery Learning dan Model Pembelajaran Konvensional pada Tingkat SMP

This research aims: (1) students' mathematical reasoning ability using the Discovery Learning learning model is higher than students' mathematical reasoning ability using conventional learning models in class VII MTs Yaspi Labuhan Deli, (2) the process of solving answers made by students in solving problems in the Discovery Learning learning model and Conventional learning model. This type of research is quantitative research with Quasi-Experimental methods. This research was conducted at MTs Yaspi Labuhan Deli. The sampling technique in this study uses Purposive Sampling techniques, namely class VII-A as a class taught with a Discovery Learning learning model and class VII-B as a class taught with a conventional learning model. The data collection instrument used was in the form of observation sheets and student mathematical reasoning ability test sheets in the form of 3 essay questions. Data analysis in this study used t-Test with Independent Sample t-Test technique with the help of SPSS 20 program. The results of this study showed that the average score of classes taught using the discovery learning model was 78,01 and classes taught using conventional learning models were 72,22. For hypothesis testing carried out using a t-test, from the calculation results obtained a value of (2.664) > (1.66757) with a Sig.2-tailed level of 0.010 < 0.05, which means that rejected and was accepted, so that it is concluded that there is a significant difference in the average mathematical reasoning ability of students using the Discovery Learning learning model and the Conventional learning model. Based on the analysis of the process of completing students' answers to the mathematical reasoning ability test that get Discovery Learning learning is better than students who get conventional learning.

Kinerja Keuangan Pada PT. Telekomunikasi Indonesia (Persero) Tbk Periode 2019-2022

This study discusses the Analysis of Liquidity Ratios, Solvency, Activity, Profitability.To measure financial performance at PT. TELECOMMUNICATIONS INDONESIA (Persero) Tbk., while the purpose of this study was to determine the condition and performance based on financial ratios. The objects used in this research are financial reports in the form of balance sheets and profit and loss reports at PT. TELECOMMUNICATIONS INDONESIA (Persero) Tbk. Period 2019-2022. The data analysis method used is the quantitative data analysis method.The results of the study were seen from the liquidity ratio in 2019-2022, the conditions were not good. In terms of solvency ratio, the condition of the company is good. In the activity ratio, the company's condition is not good because the calculation using the ratio of Total Asset Turn over, Average collections period, and Fixed Asset Turn Over shows a bad value. The profitability ratio can be said to be unfavorable because the profitability ratio analysis calculation shows that the company has not met the specified industry average standards because the profitability ratio analysis is measured using the ratio of Gross Profit Margin, Net Profit Margin, and Operating Ratio showing the same value. is not good, it can be seen that the overall level of profitability ratios is still not good.

A Hybrid Optimization Approach of Single Point Incremental Sheet Forming of AISI 316L Stainless Steel Using Grey Relation Analysis Coupled with Principal Component Analysiss

A Hybrid Optimization Approach of Single Point Incremental Sheet Forming of AISI 316L Stainless Steel Using Grey Relation Analysis Coupled with Principal Component Analysiss

Efektivitas LKPD Berbasis Inkuiri untuk Meningkatkan Kemampuan Komunikasi IPA Peserta Didik

This research aims to test the effectiveness of inquiry-based student worksheets in improving students' science communication skills. The research design used in this study is a quasi-experimental design. The research population consists of fourth-grade students in a private school for the academic year 2022/2023. One class, specifically class IV A, was chosen as the sample from the two available classes. Data collection techniques in this study were conducted through interviews, tests, and observations. The research instruments used were (1) research instruments including the learning implementation plan, and (2) data collection instruments including test instruments in the form of pre-test and post-test evaluation sheets. The communication skills gain index obtained in class IV A was 0.79 or 79.49%. Furthermore, the N-Gain Score of 0.79 is categorized as high because the N-Gain Score of 0.79 > 0.7. Therefore, the improvement in students' science communication skills using inquiry-based student worksheets is considered high, meaning that students' science communication skills using inquiry-based student worksheets have significantly improved compared to before the learning process.

Perkembangan Lembar Kegiatan Peserta Didik (LKPD) Berbasis Gambar untuk Meningkatkan Keterampilan Generic Sains

This study aims to determine the influence of using picture-based worksheets on the learning process material. It is a research and development study. The goal is to understand the process of using worksheets to improve students' critical thinking skills. This research method is used to create a specific product and test its effectiveness. The study aims to develop a product in the form of Student Activity Sheets (LKPD), evaluate the attractiveness of picture-based LKPD, and assess the effectiveness of LKPD in improving student learning outcomes.

Strategi Guru Bahasa Indonesia pada pembelajaran berbasis teks sebagai pengembangan kemampuan berpikir Siswa SMA Negeri Di Kota Pontianak

Text as a means of learning Indonesian may be developed and conditioned in such a manner that it can be a successful technique for Indonesian language teachers. Understanding text-based Indonesian learning materials takes extensive preparation and conditioning on the part of students. Purpose of this study is to analyse, comprehend, and characterise the process of text-based Indonesian language acquisition as it is implemented by instructors at public high schools in Pontianak City. This study, which used a descriptive approach with a qualitative form, also targeted Indonesian language instructors by selecting five public high schools in Pontianak as a representative sample. Direct observation and interview approaches were utilised to collect data, with data collecting devices in the form of observation sheets and interview lists. Furthermore, triangulation techniques were used in the last step of the data analysis process to test the validity of new data utilising data collecting, data condensation, data presentation, and conclusion drawing. Based on the findings of observations and interviews, it was discovered that Indonesian instructors' text-based learning methodologies may more effectively and efficiently establish an environment conducive to Indonesian language acquisition. Because students may undertake a detailed examination and analysis of a text, their comprehension of its structure and linguistic qualities is more in-depth and thorough. This research can also provide studies and has for the Merdeka Belajar curriculum to continue to provide recommendations for text-based Indonesian language learning strategies so that learning indicators and objectives can be achieved.

The Effects of Strain Rate and Anisotropy on the Formability and Mechanical Behaviour of Aluminium Alloy 2024-T3

The present study focuses on the mechanical behaviour and formability of the aluminium alloy 2024-T3 in sheet form with a thickness of 0.8 mm. For this purpose, tensile tests at quasi-static and intermediate strain rates were performed using a universal testing machine, and high strain rate experiments were performed using a split Hopkinson tension bar (SHTB) facility. The material’s anisotropy was investigated by considering seven different specimen orientations relative to the rolling direction. Digital image correlation (DIC) was used to measure specimen deformation. Based on the true stress–strain curves, the alloy exhibited negative strain rate sensitivity (NSRS). Dynamic strain aging (DSA) was investigated as a possible cause. However, neither the strain distribution nor the stress–strain curves gave further indications of the occurrence of DSA. A higher deformation capacity was observed in the high strain rate experiments. The alloy displayed anisotropic mechanical properties. Values of the Lankford coefficient lower than 1, more specifically, varying between 0.45 and 0.87 depending on specimen orientations and strain rate, were found. The hardening exponent was not significantly dependent on specimen orientation and only moderately affected by strain rate. An average value of 0.183 was observed for specimens tested at a quasi-static strain rate. Scanning electron microscopy (SEM) revealed a typical ductile fracture morphology with fine dimples. Dimple sizes were hardly affected by specimen orientation and strain rate.

Synthesis of selenium and fluorine co-doped graphitic carbon nitride for photodegradation of toxic organic pollutants and hydrogen peroxide photoproduction

Science is developing every day to race against the factual growth of industrial pollution in order to redeem the environment. In this study, modification of graphitic carbon nitride via selenium and fluoride doping was successfully conducted. Specifically, the process of co-calcination was conscripted using organic precursors, whilst the foreign elements were obtained from ammonium fluoride and selenium dioxide. The morphological assessment revealed the treated-graphitic carbon nitride possessed a flaky sheet form with high porosity and great crystalline uniformity. Photochemical investigation showed the co-doping of selenium and fluorine elevated the optical properties, including the decrement of bandgap and diminishing the recombination rate of electrons and holes. With interesting improvement in photocatalytic activity, the material was applied in persistent organic compound degradation and hydrogen peroxide production. The treatment improved the degradation percentage, in which the methylene blue removal achieved 99.96 % while the tetracycline removal reached 86.38 %. Moreover, high compatibility and great reusability over 4 cycles were also recorded. When applying the material for the generation of hydrogen peroxide, the co-doped material performance was observed to reach 3307 μM/g.h. The results concluded the advancement in material modification with great application in various aspects.